I've been repairing a few machines and I've been surprised by the number of bad diodes on CPU controlled lamps. One game had four that were bad, just on the lamps, and they were all on different portions of the matrix. On other games I've had a few that were bad on some stand ups, a few other lamps here and there, but but I haven't run across a bad one on a coil yet. Seems like bad diodes are not all that uncommon but my question is why? It doesn't seem to me that they would be taking a beating on the lamp matrix. On the coils, especially the higher voltage coils, I could see them going out but that hasn't been the case with the machines I've come across.
Is this just a case of them being made cheaply? Is there more stress on them in the lamp matrix than I realize? Is there something inherent in a pinball machine that makes them go out quickly? Or have I just run across a string of problems and I may not see many bad ones for a while?
Is this just a case of them being made cheaply? Is there more stress on them in the lamp matrix than I realize? Is there something inherent in a pinball machine that makes them go out quickly? Or have I just run across a string of problems and I may not see many bad ones for a while?
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